The collision between three cars, on the A16 London Road at Burwell was reported to the emergency services at 6.21pm this evening.
The collision involved a silver Peugeot 208, a silver Ford Fiesta, and a grey Mercedes GLA.
Officers have confirmed that one person died at the scene, and several other people have been injured. One man has been arrested.
Lincolnshire Police said: "We urgently need to hear from anyone who has captured dashcam footage or witnessed what happened.
"Please call 101, quoting incident number 372 of July 15. We will release further information when known."